Electromagnetic delay device



United States Patent 3,413,415 ELEUIROMAGNETIC DELAY DEVICE ClaudeMonin, Villennes-sur=Seine, and Pierre Moch,

Sucy-en-Brie, France, assignors to C.I.T. Compagnie Industrielle desTelecommunications, Paris,

France Filed June 2, 1965, Ser. No. 460,663 Claims priority, applicationFrance, June 3, 1964, 976,970 18 Claims. (Cl. 178-70) The presentinvention relates to arrangements for detecting the state of an electriccurrent satisfying certain requirements and for controlling thecorresponding operations while bringing in no element likely to disturbappreciably the normal operation of the circuit.

By way of example, such a device in accordance with the instantinvention will be described in the particular case when it is used as atelegraph monitoring relay; it is, however, to be understood that theinvention is not limited to such an application and that the arrangementaccording to the invention is capable of adaptation to numerousautomation problems effecting industries of very different types.

As is known, the telegraph monitoring or supervisory relay in telegraphysystems is often located in the connecting circuit of an automaticselector, series-mounted on the line wire. The connecting circuit is theunit controlled by the recorder, which establishes the conducting linkbetween the caller and the addressee. Thus, when after checking theselection of the addressee, verifying its class, and checking thepassing of the call-sign toward the addressee, the recorder closes theconnection between the caller and the addressee, a rest current isestablished, which maintains the monitoring relay in closed condition.

The telegraph modulation resulting from the passing of the message,which consists of a sequence of positive or negative periods ofrelatively short duration, must not allow the de-energizing of themonitoring relay, although this modulation may range from 50 to 200bands. On the other hand, it is also required that any negative signalof a certain duration (for instance longer than 600 milliseconds) mustproduce a de-energizing of the monitoring relay, for such a signal may,for example, correspond to the clearing signal. The de-energizing of themonitoring relay then brings about the release of the circuit ofconnected units. It is also evident that the monitoring relayseries-mounted on the line must entail no appreciable attenuation ordistortion of the telegraph signals resulting in loss of information;consequently, its impedance must be very low. In spite of thisrequirement, the relay must be sensitive and quick-moving but notsensitive to negative pulses ranging from a few mil1iseconds to severalhundreds of milliseconds.

All of the above-mentioned requirements are diflicult to achieve with aconventional electromagnetic relay in which magnetic inertia andmechanical inertia are always a large factor as a result of therelatively large dimensions necessary for insuring the motion of thearmature and of the contact springs; as a result, the solution affordedby the prior art has not been fully satisfactory in this respect.

It is the general object of the invention to provide a staticarrangement in which the above-mentioned drawbacks are avoided. Thearrangement according to the invention consists of a detectionarrangement comprising a magnetic amplifier combined with a transistor,and an electronic delay arrangement associated with the detectionarrangement.

Applicant has already developed a magnetostatic relay resulting from theassociation of a magnetic amplifier and a transistor.

3,413,415 Patented Nov. 26, 1968 In the present invention, themagnetostatic relay has been adapted to the particular problem to besolved by modifying or eliminating some components of the circuitry;besides, the use of a transistor electronic assembly, the operation ofwhich is subjected to a time constant makes it possible to obtain adelay control arrangement providing, in particular, but not exclusively,the operating conditions required from a telegraph monitoring relay.

The advantages of the arrangement according to the invention result, onthe one hand, from use of an electronic arrangement, having low powerconsumption, practically no inertia and being capable of quicklyfollowing the states of a circuit, and on the other hand, from thecharacteristic of the arrangement wherein the impedance inserted intothe circuit to be monitored does not distort in any way the telegraphsignals since it is negligible value.

These and other characteristics of the invention will be apparent fromthe following description of an example of a possible embodiment of thearrangement according to the invention, taken in connection with theaccompanying drawings, wherein:

FIGURE 1 is a wiring diagram of the'arrangement according to theinvention,

FIGURES 2, 3 and 4 are curves relating to the operation of thearrangement shown in FIGURE 1,

FIGURE 5 shows an embodiment utilizing the telegraph monitoring relayaccording to the invention.

The detection unit of the arrangement according to the invention(FIGURE 1) comprises a magnetic amplifier AMP Which is made up of asaturable magnetic core TE on which are wound several windings, t, c, p.The load winding t, series-mounted with a diode D0, is fed from an A.C.supply source AB; the diode D0 is mounted in such a way that it onlypasses the negative half-Waves. The control winding 0 is D.C. suppliedeither from a supply E or from a supply E through a protectioninductance L. The winding p is a bias winding D.C. supplied and enablingthe setting of the quiescent current of the amplifier AMP. In all cases,the control ampere-turns will be considered as the algebraic sum of theampere-turns generated by the windings c and p. The winding 2 isconnected through the diode D0 to point C at the base of the transistorTRNO, this point being also connected to one end of a resistor R theother end of which is connected to ground. The emitter of TRNO isconnected to the negative polarity u of a D.C. supply and the collectoris linked, through a ballast resistor R to the negative polarity U ofanother D.C. supply. Point M of the collector of TRNO is connected topoint N Which is in turn connected to the output terminal S on the onehand, and to the plate of a capacitor C on the other hand; the branchingat the point M of the collector is intended for controlling the releasedelay unit which will now be described.

The other plate of the capacitor C is connected to a point P which iscommon to two branches: the first of these branches comprises a diode Dseries-connected to a resistor R the free end of which is connected toground, the negative terminal of the diode being connected to point P;the second branch PQ comprises a diode D the positive terminal of whichis connected to the point P and the negative terminal to point Q. PointQ is connected, on the one hand, to one plate of a capacitor C the otherplate of which is connected to the voltage U, and on the other hand toone end of a resistor R the other end of which is connected to a commonpoint S. The point S common to the two resistors R and R is connected tothe base of a transistor TRN1 and the other end of the resistor R isconnected to the voltage U. The emitter of the transistor TRN1 isconnected to ground through the diode D the latter being arranged sothat its positive 3. terminal is grounded. The collector of transistorTRNI is connected, on the one hand, to a ballast resistor R the otherend of which is connected to the negative voltage U and, on the otherhand, to the base of transistor TRN2 (point T). The emitter oftransistor TRN1 is connected to the same biasing voltage -u as TRNO, andthe collector is connected to the output terminal S of the delayarrangement. A diode D the positive terminal of which is connected tothe voltage -U shunts the collector of transistor TRN2 as a protectionagainst over voltages from S The arrangement described above operates asfollows:

The output current I of the magnetic amplifier is a function of thealgebraic sum of the ampere-turns N I produced by windings c and p.Curve F of FIGURE 2 shows I =f(N I The voltage of point C, at the baseof transistor TRNO is a function of said current I and equals -N I Ibeing always negative because of rectifier DO. Now, the transistor TRNObecomes conducting when the voltage of point C becomes more negativethan that (u) of the emitter. There is consequently a particular valueof the current I which makes point C voltage the same as that of theemitter u. If this current is designated I which is the threshold valuefor control of transistor TRNO, above I the transistor will becomeconducting while below I it will be blocked. This value I is given by I=u/R In FIGURE 2, this value I is taken on the ordinate and through thispoint is drawn a line parallel to n i which intersects curve F in twopoints F and F To these points correspond ampere-turn respective numbersf and f Hence, if the number of negative ampere-turns has an absolutevalue larger than f the current I is larger than I and the transistor isconducting; the same applies if the number of ampere-turns isalgebraically larger than f On the other hand, if the number of controlampere-turns is bracketed between the values f and )3, I is smaller thanI and the transistor is blocked.

Thus it appears that it is possible to block or unblock the transistoraccording to the number of control ampereturns generated by the winding0. A variable current at the frequency of the A.C. supply AB flows fromthe transistor as long as the latter is conducting, in fact, theunblocked transistor oscillates at the frequency of the AC. supply AB.

FIGURE 3 shows the curve of the current I available at the terminal S ofthe arrangement. It may be seen that this current may have two valuesaccording to the control ampere-turns; a current I of constant meanvalue corresponding to the saturation current of the transistor TRNOwhen it is conducting and a zero current when the transistor is blocked.

FIGURE 4 shows the shape of the plot of the current I delivered at theoutput terminal S the axis t, is the axis of the control times of thewindings such as c, the axis t shows or represents the appearance anddisappearance times of the output current at terminal S It may be seenthat the interval between the time t when the winding c current isturned on, and the time 1' when the output current I starts flowing atthe terminal S is very short (less than a millisecond); while, theinterval between the time t when the circuit is turned off in thecontrol winding and the time 1 when the current stops flowing from theterminal S is a relatively long time r which results from the time delayarrangement as explained'hereafter.

When the transistor TRNO is blocking, the plate of C connected to P isbeing charged via R and D and the plate connected to the point M isbeing charged via R from the source voltage U. When TRNO becomesconducting, the charge on capacitor C combined with voltage U is appliedto the terminals of capacitor C As a result, the right-hand plate of Cis positive with reference to ground so that the base of transistor TRNlis positive with respect to its emitter; thus the transistor TRNI isnonconducting. However, due to the voltage U applied to point T, thetransistor TRN2 is then conducting. This state is maintained by thevariable current supplied by the collector of TRNO.

At the time when TRNO becomes blocked due to the change in the controlampere-turns N i capacitor C discharges into the series-resistors R andR thus the discharge current of C keeps blocking the transistor TRNlduring a rather long time (which depends on C R and R after TRNO hasbecome non-blocking. After this time lapse, TRNi becomes conducting andTRN2 non-conducting. A true delay arrangement is thus achieved.

Should a conventional electromagnetic relay be controlled from theterminal S such a relay will be energized when TRNO becomes conducting,and will be maintained in operating condition during the telegraphmodulation; however, it will be released some time after the final turnoff of TRNO (when the idle period of TRNO is longer than the delay rgiven by the delay arrangement).

Let it be assumed, by way of example, that the recorder operating on thewire b (FIGURE 5) causes the energizing of the conventionalelectromagnetic relay K. The contact k is made and the subscribers Aband Ab are linked for instance in the direction TRONRON from Ab which ispassing a message toward Ab The control winding 0 pertaining to thearrangement DI of FIGURE 1 according to the invention is assumed tobelong to the telegraph automatic selector AT linking the subscribers Aband A11 The wire a is a control toward the recorder for use before thesubscribers are directly connected to each other. As soon as theconnection between subscribers is achieved, the positive rest current Abtoward Ab maintains the operation of the arrangement DI and the relay Kmay then keep operating without the help of the recorder, which isdisconnected from the call. During the modulation consisting of shortnegative or positive periods, the arrangement DI remains in theoperating condition. At the end of the call when a permanent negativecurrent takes place on the line, the arrangement DI is released if theduration of this negative current is longer than the delay r provided bythe time delay arrangements (see FIGURE 4). As it is released, thearrangement DI causes the denergizing of the relay K which itself freesthe circuit being used in the automatic selector. Likewise, if nocurrent flows on the line, the arrangement DI remains idle, the biaswinding giving negative ampere-turns which correspond to a current Ilower than I (see FIG- URE 2).

A safety device has been provided so as to avoid, during a fortuitousshort circuit in the control winding, a spurious energizing of thearrangement because of the resulting current increase. This consists ofa series-connecting between the control winding 0 and an inductance Lwith the purpose of limiting the current in said Winding so that theampere-turns will never be sufiicient to cause the energizing of thearrangement under these conditions.

The arrangement according to the invention was described and shownutilizing transistors of the PNP type but it is obvious that NPN typetransistors may be used similarly in modifying the polarities of thecurrent supplies and the direction of the diodes and that othermodifications and changes may be made to the embodiment of the inventionwhich was given by way of example, without departing from the spirit andscope of the invention.

We claim:

1. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising:

detection means including a magnetic amplifier means and a transistorswitching circuit connected in series for generating a control signal inresponse to detection of a predetermined condition of a circuit of saidtelegraph exchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal.

2. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said electronic switching means including first and second transistorsoperating in a mutually exclusionary manner.

3. A detection and control arrangement, particularly for use a controlfor a monitoring relay in telegraph exchanges, capable of controlleddelayed operation of said relay comprising detection means including amagnetic amplifier means and a transistor switching circuit connected inseries for generating a control signal in response to detection of apredetermined condition of a circuit of said telegraph exchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said magnetic amplifier means including a detection winding connected tosaid circuit of said telegraph exchange for controlling the output ofsaid magnetic amplifier means in response to control from said circuit.

4. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said magnetic amplifier means including a detection winding connected tosaid circuit of said telegraph exchange for controlling the output ofsaid magnetic amplifier means in response to control from said circuit,

said magnetic amplifier means having means for rendering said transistorswitching circuit conductive and nonconductive in response to a closedand open condition, respectively, of said telegraph exchange circuit.

5. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said electronic switching means including first and second transistorsoperating in a mutually exclusionary manner,

said capacitor means including first and second capacitors connected inseries with the output of said transistor switching circuit meansincluding bias means connected to said capacitors for effecting acharging of only said first capacitor when said transistor switchingcircuit is non-conductive and for effecting discharging of said firstcapacitor and charging of said second capacitor when said transistorswitching circuit is conductive, said release delay means producing anoutput signal only when said second capacitor is in a predeterminedcharged condition.

6. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delay operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said magnetic amplifier means including a detection winding connected tosaid circuit of said telegraph exchange for controlling the output ofsaid magnetic amplifier means in response to control from said circuit,

said magnetic amplifier means having means for rendering said transistorswitching circuit conductive and non-conductive in response to a closedand open condition, respectively, of said telegraph exchange circuit,

said transistor switching circuit including a transistor having base,collector and emitter electrodes, the output of said magnetic amplifiermeans being connected to the base of said transistor, bias meansconnected to the emitter of said transistor for permitting conduction ofsaid transistor in response to a negative voltage of minimum value, saidcollector electrode being connected on the one hand to said releasedelay means and on the other hand to said bias means.

7. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said electronic switching means including first and second transistorsoperating in a mutually exclusionary manner,

said capacitor means including first and second capacitors and saidfirst and second transistors each having base, emitter and collectorelectrodes, said first capacitor being connected to the base of saidfirst transistor via a first diode and a first series resistor, negativebias means including a second series resistor connected to the base ofsaid firt transistor, a second diode connecting the point of connectionof said first capacitor and said first diode to ground, said secondcapacitor connecting the point of connection of said first diode andsaid first series resistor to said negative bias means.

8. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delay operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switching means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said electronic switching means including first and second transistorsoperating in a mutually exclusionary manner,

said capacitor means including first and second capacitors and saidfirst and second transistors each having base, emitter and collectorelectrodes, said first capacitor being connected to the base of saidfirst transistor via a first diode and a first series resistor, negativebias means including a second series resistor connected to the base ofsaid first transistor, a second diode connecting the point of connectionof said first capacitor and said first diode to ground, said secondcapacitor connecting the point of connection of said first diode andsaid first series resistor to said negative bias means,

the collector of said first transistor being connected to the base ofsaid second transistor, said base of said second transistor beingconnected to said negative bias means, the collector of said secondtransistor being connected to the output of said release delay means,over-voltage protection means connected to the collector of said secondtransistor for preventing application of overvoltages from said outputto said second transistor.

9. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange,

release delay means connected to said detection means and includingcapacitor means and electronic switch ing means for generating an outputsignal in response to actuation by said control signal and being capableof maintaining said output signal a predetermined time after extinctionof said control signal,

said electronic switching means including first and sec ond transistorsoperating in a mutually exclusionary manner,

said capacitor means including first and second capacitors and saidfirst and second transistors each having base, emitter and collectorelectrodes, said first capacitor being connected to the base of saidfirst transistor via a first diode and a first series resistor, negativebias means including a second series resistor connected to the base ofsaid first transistor, a second diode connecting the point of connectionof said first capacitor and said first diode to ground, said secondcapacitor connecting the point of connection of said first diode andsaid first series resistor to said negative bias means,

the collector of said first transistor being connected to the base ofsaid second transistor, said base of said second transistor beingconnected to said negative bias means, the collector of said secondtransistor being connected to the output of said release delay means,over-voltage protection means connected to the collector of said secondtransistor for preventing application of over-voltages from said outputto said second transistor,

said over-voltage protection means consisting of a fourth diode havingits negative terminal connected to the collector of said secondtransistor and its positive terminal connected to said negative biasmeans. 10. A detection and control arrangement, particularly for use asa control for monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange, release delay means connected to said detection means andincluding capacitor means and electronic switching means for generatingan output signal in response to actuation by said control signal andbeing capable of maintaining said output signal a predetermined timeafter extinction of said control signal,

said magnetic amplifier means including a detection winding connected tosaid circuit of said telegraph exchange for controlling the output ofsaid magnetic amplifier means in response to control from said circuit,said transistor switching circuit including a transistor having base,collector and emitter electrodes, the output of said magnetic amplifiermeans being connected to the base of said transistor, bias meansconnected to the emitter of said transistor for permitting conduction ofsaid transistor in response to a negative voltage of minimum value, saidcollector electrode being connected on the one hand to said releasedelay means and on the other hand to said bias means, said magneticamplifier means including a bias winding, a load winding and acontrolwinding and inductance means connected to said control winding toprevent accidental operation due to a short circuit in said controlWinding. 11. A detection and control arrangement, particularly for useas a control for a monitoring relay in telegraph exchanges, capable ofcontrolled delayed operation of said relay comprising detection meansincluding a magnetic amplifier means and a transistor switching circuitconnected in series for generating a control signal in response todetection of a predetermined condition of a circuit of said telegraphexchange, release delay means connected to said detection means andincluding capacitor means and electronic switching means for generatingan output signal in response to actuation by said control signal andbeing capable of maintaining said output signal a predetermined timeafter extinction of said control signal,

said electronic switching means including first and second transistorsoperating in a mutually exclusionary manner,

said magnetic amplifier means including a detection winding connected tosaid circuit of said telegraph exchange for controlling the output ofsaid magnetic amplifier means in response to control from said circuit,

sistor connected to the base of said first transistor, a second diodeconnecting the point of connection of said first capacitor and saidfirst diode to ground, said second capacitor connecting the point ofconsaid transistor switching circuit including a transistor nection Saidf' dkfde and said first Series resis' having base, collector and emitterelectrodes, the tor to said negatlve blas means, output of said magneticamplifier means being conthe collector of said first transistor beingconnected to nected to the base of said transistor, bias means conthebase of said second transistor, said base of said nected to the emitterof said transistor for permitting second transistor being connected tosaid negative conduction of said transistor in response to a negabiasmeans, the collector of said second transistor tive voltage of minimumvalue, said collector elecbeing connected to the output of said releasedelay trodes being connected on the one hand to said means, over-voltageprotection means connected to release delay means and on the other handto said the collector of said second transistor for preventing biasmeans, application of over-voltages from said output to said capacitormeans including first and second capacisaid second transistor,

tors and said first and second transistors each havsaid over-voltageprotection means consisting of a ing base, emitter and collectorelectrodes, said first fourth diode having its negative terminalconnected capacitor being connected to the base of said first to thecollector of said second transistor and its transistor via a first diodeand a first series resistor, positive terminal connected to saidnegative bias negative bias means including a second series remeans,sistor connected to the base of said first transistor, a said magneticamplifier means including a bias windsecond diode connecting the pointof connection of ing, a load winding and a control winding and insaidfirst capacitor and said first diode to ground, ductance means connectedto said control winding said second capacitor connecting the point ofconto prevent accidental operation due to a short circuit nection ofsaid first diode and said first series rein said control winding. sistorto said negative bias means, 13. A detection and control arrangement,particularly the collector of said first transistor being connected tofor u e as a control for a monitoring relay in telegraph the base ofsaid second transistor, said base of said exchange circuits capable ofcontrolled delayed operation second transistor being connected to saidnegative bias of said relay comprising means, the collector of saidsecond transistor being detection means for generating a control signalin reconnected to the output of said release delay means, sponse todetection of a closed circuit condition in over-voltage protection meansconnected to the cola selected telegraph exchange circuit, lector ofsaid second transistor for preventing applirelease delay means connectedto said detection means cation of over-voltages from said second outputto for generating an output signal in response to said said secondtransistor. control signal including capacitor means for main- 12. Adetection and control arrangement, particularly taining said outputsignal a predetermined time after for use as a control for a monitoringrelay in telegraph exchanges, capable of controlled delay operation ofsaid relay comprising detection means including a magnetic amplifiermeans and a transistor switching circuit connected in series forgenerating a control signal in response to detection of a predeterminedcondition of a circuit of said extinction of said control signal,

said output signal being applied to said relay to effect operationthereof.

14. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchange circuits, capableof controlled delayed operation of said relay comprising telegraphexchange,

detection means for generating a control signal in rerelease delay meansconnected to said detection means sponse to detection of a closedcircuit condition in and including capacitor means and electronicswitcha selected telegraph exchange circuit, ing means for generating anoutput signal in rerelease delay means connected to said detection meanssponse to actuation by said control signal and being for generating anoutput signal in response to said capable of maintaining said outputsignal a precontrol signal including capacitor means for maindeterminedtime after extinction of said control taining said output signal apredetermined time after signal, extinction of said control signal,

said electronic switching means including first and secsaid outputsignal being applied to said relay to effect 0nd transistors operatingin a mutually exclusionary operation thereof, manner, said detectionmeans including a magnetic amplifier said magnetic amplifier meansincluding a detection having a control winding connected to saidtelegraph winding connected to said circuit of said telegraph exchangecircuit and inductance means connected to exchange for controlling theoutput of said magnetic said control Winding to prevent accidentaloperation amplifier means in response to control from said of saidamplifier, due to short circuits in said control circuit, Winding.

said transistor switching circuit including a transistor 15. A detectionand control arrangement, particularly having base, collector and emitterelectrodes, the output of said magnetic amplifier means being connectedto the base of said transistor, bias means for use as a control for amonitoring relay in telegraph exchange circuits capable of controlleddelayed operation of said relay comprising connected to the emitter ofsaid transistor-for perdetection means for generating a control signalin remitting conduction of said transistor in response sponse todetection of a closed circuit condition in a to a negative voltage ofminimum value, said colselected telegraph exchange circuit,

lector electrodes being connected on the one hand release delay meansconnected to said detection means to said release delay means and on theother hand for generating an output signal in response to said to saidbias means, control signal including capacitor means for mainsaidcapacitor means including first and second capacitaining said outputsignal a predetermined time after tors and said first and secondtransistors each havextinction of said control signal,

ing base, emitter and collector electrodes, said first said outputsignal being applied to said relay to effect capacitor being connectedto the base of said first operation thereof,

transistor via a first diode and a first series resistor, said capacitormeans including first and second capacnegative bias means including asecond series reitors connected in series with the output of saiddetection means, bias means connected to said first and secondcapacitors for efiFecting charging of said first capacitor anddischarging of said second capacitor in absence of said control signaland discharging of said first capacitor and charging of said secondcapacitor in response to said control signal.

16. A detection and control arrangement, particularly for use as acontrol for a monitoring relay in telegraph exchange circuits capable ofcontrolled delayed operation of said relay comprising detection meansfor generating a control signal in response to detection of a closedcircuit condition in a selected telegraph exchange circuit, releasedelay means connected to said detection means second capacitors foreffecting charging to said first capacitor and discharging of saidsecond capacitor in absence of said control signal and discharging ofsaid first capacitor and charging of said second capacitor in responseto said control signal,

said release delay means further including transistor control means forgenerating said output signal in response to a detection of apredetermined charged condition of said second capacitor,

over-voltage protection means connected to said transistor control meansfor preventing application of excessive voltage from said relay to saidtransistor control means.

18. A detection and control arrangement, particularly for generating anoutput signal in response to said control signal including capacitormeans for maintaining said output signal a predetermined time afterextinction of said control signal,

said output signal being applied to said relay to effect operationthereof,

said capacitor means including first and second capacitors connected inseries with the output of said detection means, bias means connected tosaid first and second capacitors for effecting charging to said firstcapacitor and discharging of said second capacitor in absense of saidcontrol signal and discharging of said first capacitor and charging ofsaid second capacitor in response to said control signal,

said release delay means further including transistor control means forgenerating said output signal in response to a detection of apredetermined charged condition of said second capacitor.

17. A detection and control arrangement, particularly 15 for use as acontrol for a monitoring relay in telegraph exchange circuits, capableof controlled delay operation of said relay comprising detection meansfor generating a control signal in response to detection of a closedcircuit condition in a selected telegraph exchange circuit,

release delay means connected to said detection means for generating anoutput signal in response to said control signal including capacitormeans for maintaining said output signal a predetermined time afterextinction of said control signal,

said output signal being applied to said relay to effect operationthereof,

said detection means including a magnetic amplifier having a controlwinding connected to said telegraph exchange circuit and inductancemeans connected to said control winding to prevent accidental operationof said amplifier due to short circuits in said control Winding,

for use as a control for a monitoring relay in telegraph exchangecircuits capable of controlled delay operation of said relay comprisingdetection means for generating a control signal in response to detectionof a closed circuit condition in a selected telegraph exchange circuit,release delay means connected to said detection means for generating anoutput signal in response to said control signal including capacitormeans for maintaining said output signal a predetermined time afterextinction of said control signal, said output signal being applied tosaid relay to effect operation thereof, said capacitor means includingfirst and second capacitors connected in series with the output of saiddetection means, bias means connected to said first and said capacitormeans including first and second capacitors connected in series with theoutput of said detection means, bias means connected to said first andsecond capacitors for effecting charging of said first capacitor anddischarging of said second capacitor in absence of said control signaland discharging of said first capacitor and charging of said secondcapacitor in response to said control signal,

said release delay means further including transistor control means forgenerating said output signal in response to a detection of apredetermined charged condition of said second capacitor.

No references cited.

THOMAS B. HABECKER, Primary Examiner.

1. A DETECTION AND CONTROL ARRANGEMENT, PARTICULARLY FOR USE AS ACONTROL FOR A MONITORING RELAY IN TELEGRAPH EXCHANGES, CAPABLE OFCONTROLLED DELAYED OPERATION OF SAID RELAY COMPRISING: DETECTION MEANSINCLUDING A MAGNETIC AMPLIFIER MEANS AND A TRANSISTOR SWITCHING CIRCUITCONNECTED IN SERIES FOR GENERATING A CONTROL SIGNAL IN RESPONSE TODETECTION OF A PREDETERMINED CONDITION OF A CIRCUIT OF SAID TELEGRAPHEXCHANGE, RELEASE DELAY MEANS CONNECTED TO SAID DETECTION MEANS ANDINCLUDING CAPACITOR MEANS AND ELECTRONIC SWITCHING MEANS FOR GENERATINGAN OUTPUT SIGNAL IN RESPONSE TO ACTUATION BY SAID CONTROL SIGNAL ANDBEING CAPABLE OF MAINTAINING SAID OUTPUT SIGNAL A PREDETERMINED TIMEAFTER EXTINCTION OF SAID CONTROL SIGNAL.